- /* default mapping from samplers to texture units */
- for (i = 0; i < MAX_SAMPLERS; i++)
- prog->SamplerUnits[i] = i;
+ /* Uniforms that lack an initializer in the shader code have an initial
+ * value of zero. This includes sampler uniforms.
+ *
+ * Page 24 (page 30 of the PDF) of the GLSL 1.20 spec says:
+ *
+ * "The link time initial value is either the value of the variable's
+ * initializer, if present, or 0 if no initializer is present. Sampler
+ * types cannot have initializers."
+ *
+ * So we only initialise ARB assembly style programs.
+ */
+ if (is_arb_asm) {
+ /* default mapping from samplers to texture units */
+ for (unsigned i = 0; i < MAX_SAMPLERS; i++)
+ prog->SamplerUnits[i] = i;
+ }